Data centers requires a lot of energy due to that data centers count as the buildings also contains servers, cooling equipment, IT-equipment and power equipment. As the cooling solution for many data centers around the world right now, the compressor-based cooling solution counts for around 40% of the total energy consumption. A non-compressor-based solution that is used in some data centers, but also is in a research phase is the free cooling application. Free cooling means that the outside air is utilized to cool down the data center and there are two main technologies that contains within free cooling: airside free cooling and waterside free cooling. The purpose of this master thesis is to analyze two types of coils; one corrugated and the other one smooth, providing from Bensby Rostfria, to investigate if it is possible to use free cooling in 5G EDGE data center in Luleå, with one of these coils. The investigation will be done during the warmest day in summer. This because, according to weather data, Luleå is one candidate where this type of cooling system could be of use.

The project was done through RISE ICE Datacenter where two identical systems was built next to each other with two corrugated hoses of different diameter and two smooth tubes with different diameter. The variables that was measured was the ambient temperature within the data hall, the water temperature in both water tanks, the temperature out from the system, the temperature in to the system and the mass flow of the air that was going to go through the system. The first thing that was done was to do fan curves to easier choose which input voltages for the fans that was of interest to do further analysis on. After that was done, three point was taken where the fan curve was of most increase. The tests were done by letting the corrugated hoses and smooth tubes to be in each of the water tanks and fill it with cold water. It was thereafter the coils that should warm the water from 4,75 °C – 9,75 °C, because of that the temperature in the data center was around 15 °C. The rising in particularly these temperatures was chosen because it is seen that to use free cooling the temperature differences must be at least 5 °C. The tests were done three times to get a more reliable result. All the data was further taken in to Zabbix and to further analysis in Grafana.

When one test was done the files was saved from Grafana to Excel for compilation, and thereafter to Matlab for further analysis. The first thing that was analyzed was if the three different tests with the same input voltages gave similar results in the water temperature in the tank and the temperature out from the system. Thereafter, trendlines was built to investigate the temperature differences in and out of the system, the temperature differences in and the water temperature in the tank, the mass flow and the cooling power. That trendline was further in comparison to each other, which was 2D-plots between the cooling power and the temperature differences between the inlet and the water. Thereafter the both coils could compare to each other to see which of them that gave the largest cooling power and was most efficient to install in a future 5G data center module. The conclusion for this master thesis is that the corrugated hose will give a higher cooling power with higher temperature differences outside, but during the warmest summer day it was distinctly the smooth tube that gave the largest cooling power and therefore the best result. The smooth tube also got, through hand calculations, the larger amount of pipe that was necessary to cool down the 5G module, but the smallest water tank. It was also shown that for the warmest summer day, a temperature in the water tank of 24 °C is the best, compared to 20 °C and 18 °C. The amount of coil that is needed to cool down the data center with a temperature in the water tank at 24 °C and how large the water tank differs between the two types of coils. For the corrugated hose a length of 1.8 km and a water tank of 9.4 m3. As for the smooth tube a length of 1.7 km and a water tank volume of 12 m3. As can be seen throughout this project is that this type of cooling equipment is not the most efficient for the warmest summer day but could easily be used for other seasons.

Hydro power plants are an essential part of the infrastructure in Sweden as they stand for a large amount of the produced electricity and are used to regulate supply and demand on the electricity grid. Other renewable energy sources, such as wind and solar power, have become more popular as they contribute to a fossil free society. However, wind and solar power are intermittent energy sources causing the demand for regulating power on the grid to increase. Hydro power turbines are designed to operate at a certain design point with a specific flow rate. The plants are operated away from the design point when used to regulate the supply and demand of electricity. This can cause a specific flow phenomenon to arise in the draft tube at part load conditions called a Rotating Vortex Rope (RVR) which causes dangerous pressure fluctuation able to damage blades and bearings.

A solution to mitigate a RVR is to inject pulsating momentum into the draft tube by using an actuator operating at a certain frequency. A literature study was conducted and three techniques were numerically simulated using ANSYS Workbench 19.0 R3; a fluidic oscillator, a piston actuator and a synthetic jet actuator. A dynamic mesh was used to simulate the movement of the piston actuator and diaphragm of the synthetic actuator whilst the mesh of the fluidic oscillator was stationary. The relative errors of the three numerical models were all below 3 %. All devices showed promising results and could potentially be used to mitigate a RVR because they all have the ability to produce high energy jets. The fluidic oscillator had an external supply of water, whereas the other two did not, which means that it could inject the largest mass flow. The piston actuator required a driving motor to move the piston. The diaphragm of the synthetic jet actuator was moved by a Piezoelectric element. Advantages of the fluidic oscillator are that it has no moving parts, in contrary to the two other devices, it can directly be connected to the penstock or draft tube to obtain the required water supply and it is easy to install. It will most likely also be smaller compared to the other two for the same mass flow rate. It does however not generate a pulsating jet, but rather an oscillating jet. The other two devices generate pulsating jets, but have problems with low pressure areas during the intake stroke which can cause cavitation problems. These areas cause the formation of vortex rings close to the outlet. Simulations showed that a coned piston together with a coned cylinder outlet could decrease losses by almost 16 % compared to a normal piston and cylinder. It also decreased the risk for cavitation and the required force to move the piston. Otherwise, a shorter stroke length for a constant cylinder diameter or a longer stroke length for a constant volume displacement also decreased the risk for cavitation and required force. The gasket between the piston and cylinder is a potential risk for leakage. A solution to avoid critical low pressure areas is to install an auxiliary fluid inlet or valve which opens at a certain pressure for the piston actuator as well as the synthetic jet actuator. This will also allow larger mass flow rates and a higher injected momentum. Both devices are more complicated to install and require likely more maintenance compared to the fluidic oscillator. However, there exist many possible design options for the piston actuator. The design of the synthetic jet is more limited because of the diaphragm. The amplitude of the diaphragm also has a direct effect on the pressure levels. The losses increased proportional to the mass flow to the power of three which suggests that it is better to install many small actuators instead of a few large ones.

Aim: The aim of this study was to describe occupational therapists’ experiences of specialized palliative care. Method: A qualitative study was conducted. The participants consisted of eleven occupational therapists working in specialized palliative care. The data collection was conducted with semi-structured interviews using telephone and the data was analyzed with a qualitative content analysis. Result: The analysis resulted in an overall theme; To enable occupation and participation until the end of life with three categories; Flexibility and compliance, The goal of interventions is quality of life, The multifunctional team. The result shows that the occupational therapists experiences is that conversation and compliance form the basis of the therapeutic relationship required to support clients in their process and implement interventions based on the clients individual needs and requests. The result shows that it takes foresight and flexibility to meet the clients rapid changes. The aim with interventions is that clients shall experience quality of life till the end of life. This is for instance made with compensatory interventions, guidance, adapting activities and environment and symptomatic relief. Working in a multi-professional team is the basis for meeting the client's physical, mental, social and existential needs, where the team also stands for knowledge exchange and as an emotional support. Conclusion: The result can contribute with understanding and knowledge of the approach and working method used by the occupational therapist in palliative care to meet the client's needs and enable activity and participation towards the end of life. The study can also contribute to an understanding of the importance of teamwork in palliative care and why the occupational therapist is needed in the palliative care teams. Further research is needed on the occupational therapists unique competence and how it is acquired. Further research is needed on occupational therapy in various palliative care forms to clarify occupational therapy in palliative care and to create a common theoretical basis.

In this master thesis it have been investigated how the stiffness of a seat affect the risk of neck injuries, e.g whiplash associated disorders, in a rear end low velocity car collision using a female human body model, HBM, and if dividing the seat into several sections with different stiffnesses. The project is performed in collaboration with CEVT, China Euro Vehicle Technology, a innovation center of the Geely Holding Group. The HBM used is the VIVA open source HBM developed by Chalmers University of Technology together with Volvo Cars, The Swedish National Road and Transport ResearchInstitute (VTI) and Folksams forskningsstiftelse. Two different seats were investigated, a generic seat and the seat of the existing Lynk&Co 01. The stiffness of the seat had a significant impact on the risk of neck injuries, but does not seem to be a good idea to divide the seat into several sections since the height of the individual in the seat influence what stiffness is optimal for each section. It was also discovered that the relative distance between the head and the headrest at the moment of impact has a great affect on the risk of neck injuries.

Smart tools for audio production have been making its way into modern audio production and is getting more popular in studio and postproduction work. In live sound however, there is few alternatives that exist. In this study live sound engineers experienced in live music sound reinforcement were interviewed about how they use gain and what considerations they make when adjusting gain. The aim of this study was to use their answers to create the foundation of a framework to an algorithm that can adjust gain automatically. The interviews were semi-structured, and the transcriptions were analysed using grounded theory. From the transcripts five categories were created and further divided into subcategories for deeper analysis. The study showed that the data in the study could not easily be proceduralized but instead two alternative ways of implementing this in practice, one that monitors the input signals and passes the information to the engineer. And another that adds a control layer to the monitoring where the parameter can be selected based on mixing strategy and the algorithms control can be switched on or off.

This study have identified and analysed anomalous meteor head echos detected by the MU Radar, as well as reproduced an interference anomaly through simulation with the use of an existing analysis pipeline. The parameters used to detect anomalies were High Start Altitude [HSAA], High Radar Cross Section [HRCSA] and High Eccentricity [HEA]. A cut-off of the head echo signal were the cause of the HSAA’s. Trail echos misclassified as head echoes and low agreement with the multiple emitter location and signal parameter estimation (MUSIC) method gave rise to the HRCSA’s. The majority of the HEA’s were given a falsely high eccentric- ity due to high beam angle and trail echos detection. Three found HEA’s showed a small possibility of having an hyperbolic orbit. Additionally, a simulation was made which concluded that signal interference will occur between two echos if the range is the same to the radar.

The cab assembly line in Oskarshamn is one of the world's most high tech production unit. With close to 300 robots the cab is assembled with merely programmed robots and no input from humans. Scania CV AB is a world leading manufacturer of trucks with high influence on the market globally.

Even though robots do most of the work, there have been human brains behind the robot execution, and there is constant work ongoing to further increase efficiency and cycle times to meet the increasing global demand for logistics services. The robots are mainly programmed offline, using the ABB software Robotstudio, which basically creates a digital representation of the actual control system without interfering with the production. Testing upgraded programs as well as simulating them offline before implementation is an essential daily operation to make the production meet the demands.

This thesis is divided into two objectives, one theoretical and one practical. The theoretical part focuses on the software, and consists of a critical analysis of a series of different software solutions for programming robots offline, as well as a look into how the offline programming processes work today in-house. The practical objective is to further improve the quality of the simulations conducted through creating tools to answer the calls from functional packages for the different processing equipment used on site. These functional packages lets you perform spot welding, gluing or gripping for instance, and as it is an outsourced service a lot of the coding is encrypted which prevents simulations being conducted with the pre-programmed routines, it makes the simulations crash.

This report presents conclusions made regarding the use of offline programming equipment both in the regards of daily operations as well as long term strategies with digital twins and digitization. It also proves that the functional packages still can be simulated even though the code has been manipulated and encrypted at one point. It holds the complete ways of how to, from a 3D CAD model, create mechanisms, synchronize external axes, and creating smart components to answer digital inputs and presenting digital outputs to the system to have a fully functional simulation run.

Purpose: The aim of this study was to describe occupational therapists’ experience of using Constraint Induced Movement Therapy for children with hemiplegic cerebral palsy. Methods: A qualitative method was chosen to describe the subjective experiences of the occupational therapists. Eight semi structured interviews were conducted with occupational therapists that were working at different centres for child and adolescent rehabilitation in this country, thereafter the collected data was analysed using qualitative content analysis. Result: The results were divided into four categories: The occupational therapist’s support, The importance of the network, Adaptation of the intervention and The organisational structures. The result indicate that the intervention should be centred on the child’s motivation and play in collaboration with the child’s social network and the intervention usually leads to an extended activity repertoire for the child. Furthermore, the result indicates the intervention to be time consuming, demanding extensive structure and resources, which led to the intervention was performed by only a few occupational therapists. It also appeared that collegial support among occupational therapists promotes the implementation of Constraint Induced Movement Therapy. Conclusion: The study show that the child’s range of activities often were improved when using Constraint Induced Movement Therapy, but this could not be proven with today’s assessment instrument.

Decentralized retail sites are facing increased challenges with retail digitalization. Another challenge is that societies are progressing towards sustainable cities. As the cities grow the decentralized retail sites are becoming a centralized part of the city. Järfälla municipality in Stockholm County, mentions in their latest comprehensive plan that Barkarby Retail Center will have an urban development scheme in 2050. The plan also states that the area will be a part in connecting the local municipality centers.

The aim of this study was to determine the possibilities of reducing car dependency in decentralized retail sites with compact development. The study resulted in an area proposal for Barkarby Retail Center, where the existing retail were adapted to an urban development with an improved accessibility and continued economic value.

Theoretical studies concluded that compact development is a working strategy to make people drive less, if it is combined with an improved public transport. The studies also concluded that even though the retail is getting more digitalized, the importance of physical stores is still proven to be important for profitability. By minimizing the retail space and implementing home delivery for bulky goods, the decentralized retail could be adapted to an urban development scheme. In order to maintain the accessibility of the area, the area’s pedestrian and bicycle networks were improved, parking spaces were gathered at the outskirts of the area and a new public transport line was drawn through the area.

The aim of the study was to explore occupational therapists experience of working with individuals diagnosed with schizophrenia in forensic psychiatric inpatient care. The authors chose a qualitative methodology and conducted eight semi-structured interviews with occupational therapists who worked in forensic psychiatry in south, middle and north of Sweden. The collected data was transcribed and analyzed according to a qualitative analysis method which resulted in four categories and four subcategories; Occupational evaluation, assessments and the use of assessment instruments with patients with schizophrenia; Impacts of factors and guidelines on evaluation work and Assessments and evidence based assessment instruments in inpatient care, Security and restriction guidelines in a structured environment; Impacts of restriction on prescribing aids and Opportunities and challenges to work in a constrained environment, Opportunities to work with activity and skills with patients with schizophrenia and Work with motivation, initiative and activity to increase participation. The result showed occupational therapists' experience of working in an environment adapted to safety and restrictions with individuals diagnosed with schizophrenia. The study shows the importance of occupational therapy competence in working with patients who have been diagnosed with schizophrenia to enable participation and independence despite the impact of the environment. More research is required on how occupational therapeutic skills and assessment tools should be adapted to a structured and controlled environment to enable more quality-assured rehabilitative care for patients who have schizophrenia in forensic psychiatric care.

This article proposes a Deep Learning (dl) method to enable fully autonomous flights for low-cost Micro Aerial Vehicles (MAVs) in unknown dark underground mine tunnels. This kind of environments pose multiple challenges including lack of illumination, narrow passages, wind gusts and dust. The proposed method does not require accurate pose estimation and considers the flying platform as a floating object. The Convolutional Neural Network (CNN) supervised image classifier method corrects the heading of the MAV towards the center of the mine tunnel by processing the image frames from a single on-board camera, while the platform navigates at constant altitude and desired velocity references. Moreover, the output of the CNN module can be used from the operator as means of collision prediction information. The efficiency of the proposed method has been successfully experimentally evaluated in multiple field trials in an underground mine in Sweden, demonstrating the capability of the proposed method in different areas and illumination levels.

The usage of Micro Aerial Vehicles (MAVs) in different applications is gaining attention, however one of the main challenges is to provide collision free paths, despite the uncertainties in localization, mapping, or path planning. This article proposes a novel collision-free path planner for MAV navigation in confined environments, while not being dependent on the information of the localization, only relying on 2D local point-cloud data. The proposed backup path planner generates velocity commands for a trajectory-following controller, while guaranteeing a safety distance from all points in the local-point-cloud. The proposed method considers the kinematics of the MAV and can be extended to any robotics application, such as ground vehicles. The proposed method is evaluated in a Gazebo simulation environment and successfully provides a collision-free navigation.

High-strength concrete (HSC) is highly applicable to the construction of heavy structures. However, shear strength (Ss) determination of HSC is a crucial concern for structure designers and decision makers. The current research proposes the novel models based on the combination of adaptive neuro-fuzzy inference system (ANFIS) with several meta-heuristic optimization algorithms, including ant colony optimizer (ACO), differential evolution (DE), genetic algorithm (GA), and particle swarm optimization (PSO), to predict the Ss of HSC slender beam. The proposed models were constructed using several input combinations incorporating several related dimensional parameters such as effective depth of beam (d), shear span (a), maximum size of aggregate (ag), compressive strength of concrete (fc), and percentage of tension reinforcement (ρ). To assess the impact of the non-homogeneity of the dataset on the prediction result accuracy, two possible modeling scenarios, (i) non-processed (initial) dataset (NP) and (ii) pre-processed dataset (PP), are inspected by several performance indices. The modeling results demonstrated that ANFIS-PSO hybrid model attained the best prediction accuracy over the other models and for the pre-processed input parameters. Several uncertainty analyses were examined (i.e., model, variables, and data), and results indicated predicting the HSC shear strength was more sensitive to the model structure uncertainty than the input parameters.

Agricultural land in the south of Iraq provides habitat for several types of living creatures. This land has a significant impact on the ecosystem. The agricultural land of Al-Hawizeh marsh covers an area of more than 3500 km2 and is considered an enriched resource to produce several harvests. A total of 74% of this area suffers from a high degree of salinity and chemical pollution, which needs to be remedied. Several human-made activities and post-war-related events have caused radical deterioration in soil quality in the agricultural land. The goal of this research was to integrate mathematical models, remote sensing data, and GIS to provide a powerful tool to predict, assess, monitor, manage, and map the salinity and chemical parameters of iron (Fe), lead (Pb), copper (Cu), chromium (Cr), and zinc (Zn) in the soils of agricultural land in Al-Hawizeh marsh in southern Iraq during the four seasons of 2017. The mathematical model consists of four parts. The first depends on the B6 and B11 bands of Landsat-8, to calculate the soil moisture index (SMI). The second is the salinity equation (SE), which depends on the SMI result to retrieve the salinity values from Landsat-8 images. The third part depends on the B6 and B7 bands of Landsat-8, which calculates the clay chemical index (CCIs). The fourth part is the chemical equation (CE), which depends on the CCI to retrieve the chemical values (Fe, Pb, Cu, Cr, and Zn) from Landsat-8 images. The average salinity concentrations during autumn, summer, spring, and winter were 1175, 1010, 1105, and 1789 mg/dm3, respectively. The average Fe concentrations during autumn, summer, spring and winter were 813, 784, 842, and 1106 mg/dm3, respectively. The average Pb concentrations during autumn, summer, spring, and winter were 4.85, 3.79, 4.74, and 7.2 mg/dm3, respectively. The average Cu concentrations during autumn, summer, spring, and winter were 3.9, 3.1, 4.45, and 7.5 mg/dm3, respectively. The average Cr concentrations during autumn, summer, spring, and winter seasons were 1.28, 0.73, 1.03, and 2.91 mg/dm3, respectively. Finally, the average Zn concentrations during autumn, summer, spring, and winter were 8.25, 6, 7.05, and 12 mg/dm3, respectively. The results show that the concentrations of salinity and chemicals decreased in the summer and increased in the winter. The decision tree (DT) classification depended on the output results for salinity and chemicals for both SE and CE equations. This classification refers to all the parameters simultaneously in one stage. The output of DT classification results can display all the soil quality parameters (salinity, Fe, Pb, Cu, Cr, and Zn) in one image. This approach was repeated for each season in this study. In conclusion, the developed systematic and generic approach may constitute a basis for determining soil quality parameters in agricultural land worldwide.

Outotec Sweden AB works in the field of precious metal refining. Silver electrorefining is one of Outotec’s technologies widely applied in numerous silver refining plants worldwide. During this project a specific section in a silver refinery plant has been investigated. Today’s system provided by Outotec utilises gravity as a means of transport of the slurry consisting of refined silver crystals and silver electrolyte. The slurry is directed from the electrolysis cells through pipes mounted in an angle towards a separation tank. This solution requires three floors of the building of the refinery plant. The goal of this project was to develop concepts which would transport the slurry of silver crystals from the electrolysis cells to a separation tank within a single floor of the building. The implementation of such a system would result in lowering the overall investment cost of the refinery by at least 7 %.

Ulrich & Eppinger’s product development process has been utilised in this thesis work which is a six step sequential method for development of products. Through this process, four concepts for transportation of silver crystal slurry were developed, analysed and cost estimated - Syringe, Drop to circulation tank, Suction Pump and Conveyor. The syringe concept eliminated the need for a single floor of the refinery, which translated to total projected investment cost of 337 000 SEK and an overall investment savings of 8.3 %. Drop to circulation tank eliminated the need for two floors which lead to a total estimated cost of 862 000 SEK. This corresponded to an overall investment savings of 16.5 %. The two final concepts - suction pump and conveyor was estimated to cost 346 000 and 337 000 SEK respectively. Both of the concepts resulted in a total projected savings of the overall investment by 8.3%, eliminating the need for one of the three floors in the refinery. The conclusion is that each of the concepts developed surpassed the goal of lowering the overall investment of the refinery by at least 7%. Three of the four concepts eliminated the need for one floor while the final one, drop to circulation tank, eliminated the need for two of the three floors.

The concepts must be tested before implemented. This could either be conducted by approximating the electrolyte as water and silver crystals as metal shavings or by sludge. It would however be beneficial if a test rig is constructed for each concept and they are tested with the same mixture of silver slurry that is transported in Outotec’s existing refineries.

The circulation tank should also be installed on the same floor as the electrolysis cells and the separation tank for the syringe, conveyor and suction pump concepts. This was never investigated by the authors since it was a limitation stated as the project was initiated. This component was however included in the drop to circulation tank concept since it was considered being part of the transportation system. If the circulation tank is installed on the same floor as the other components it will result in eliminating the need for two floors, which would ultimately lead to a substantial decrease in overall investment cost.

In a coastal environment, this paper investigated the formation process and the cumulative shape of subaqueous mounds formed by hopper dredged discharges. Hydrological observations and field tests were performed to examine the flow features and ultimately generated morphology characteristics. A high-precision digital elevation model (DEM) was established by multi-beam depth sweeping (MBDS) in the experiment. Particular attention was paid to the formation of the mounds, the three-dimensional shape and the influence factors. The field measurements showed that the mounds were roughly symmetrical in space, and the tidal current, though of weak strength, played a certain role in shaping the profiles. Cone and volcanic cone mound tops were observed, featuring the main top shapes. The height and covered area of the mounds were proportional to the amount of dumped sediment, and they were also affected a lot by the water depth. The results of superimposed tests showed that the second placement over the existing mound resulted in a similar overall shape, but there was pronounced movement around the mound; additional discharged volumes at the same location mainly increased the mound height. The field tests provided a reference for understanding the sediment dumping in other similar coastal areas.

The check dams in grassed stormwater channels enhance infiltration capacity by temporarily blocking water flow. However, the design properties of check dams, such as their height and spacing, have a significant influence on the flow regime in grassed stormwater channels and thus channel infiltration capacity. In this study, a mass-balance method was applied to a grassed channel model to investigate the effects of height and spacing of check dams on channel infiltration capacity. Moreover, an empirical infiltration model was derived by improving the modified Kostiakov model for reliable estimation of infiltration capacity of a grassed stormwater channel due to check dams from four hydraulic parameters of channels, namely, the water level, channel base width, channel side slope, and flow velocity. The result revealed that channel infiltration was increased from 12% to 20% with the increase of check dam height from 10 to 20 cm. However, the infiltration was found to decrease from 20% to 19% when a 20 cm height check dam spacing was increased from 10 to 30 m. These results indicate the effectiveness of increasing height of check dams for maximizing the infiltration capacity of grassed stormwater channels and reduction of runoff volume.

Considering the scouring depth downstream of weirs is a challenging issue due to its effect on weir stability. The adaptive neuro-fuzzy inference systems (ANFIS) model integrated with optimization methods namely cultural algorithm, biogeography based optimization (BBO), invasive weed optimization (IWO) and teaching learning based optimization (TLBO) are proposed to predict the maximum depth of scouring based on the different input combinations. Several performance indices and graphical evaluators are employed to estimate the prediction accuracy in the training and testing phase. Results show that the ANFIS-IWO offers the highest prediction performance (RMSE = 0.148) compared to other models in the testing phase, while the ANFIS-BBO (RMSE = 0.411)ANFIS-TLBO-M3 RMSEtesting=0.411, CCtesting~0.00) provides the lowest accuracy. The findings obtained from the uncertainty analysis of prediction modeling indicate that the input variables variability R-factor=1.72has a higher impact on the predicted results than the structure of models. In general, the ANFIS-IWO can be used as a reliable and cost-effective method for predicting the scouring depth downstream of weirs.

Development of landslide predictive models with strong prediction power has become a major focus of many researchers. This study describes the first application of the Hyperpipes (HP) algorithm for the development of the five novel ensemble models that combine the HP algorithm and the AdaBoost (AB), Bagging (B), Dagging, Decorate, and Real AdaBoost (RAB) ensemble techniques for mapping the spatial variability of landslide susceptibility in the Nam Dan commune, Ha Giang province, Vietnam. Information on 76 historical landslides and ten geo-environmental factors (slope degree, slope aspect, elevation, topographic wetness index, curvature, weathering crust, geology, river density, fault density, and distance from roads) were used for the construction of the training and validation datasets that are the prerequisites for building and testing the proposed models. Using different performance metrics (i.e., the area under the receiver operating characteristic curve (AUC), negative predictive value, positive predictive value, accuracy, sensitivity, specificity, root mean square error, and Kappa), we verified the proficiency of all five ensemble learning techniques in increasing the fitness and predictive powers of the base HP model. Based on the AUC values derived from the models, the ensemble ABHP model that yielded an AUC value of 0.922 was identified as the most efficient model for mapping the landslide susceptibility in the Nam Dan commune, followed by RABHP (AUC = 0.919), BHP (AUC = 0.909), Dagging-HP (AUC = 0.897), Decorate-HP (AUC = 0.865), and the single HP model (AUC = 0.856), respectively. The novel ensemble models proposed for the Nam Dan commune and the resultant susceptibility maps can aid land-use planners in the development of efficient mitigation strategies in response to destructive landslides.

Many of today’s engineering advancements rely on minerals such as copper, gold and iron. For this reason, the mining industry plays an important role for the development of society and technological wonders. Mining excavators are commonly used tools for extracting the minerals from the mine. Mining excavators are large machines used to breakdown, penetrate and load the rock ores onto trucks that transport the minerals. During the dynamic loading, the excavator bucket experiences significant amount of wear and tear that negatively affects the production by increasing the downtime. The bucket teeth are arguably the most worn parts of the bucket and are responsible for significant amounts of downtime. This thesis aims to provide a better understanding of the load and wear on the bucket teeth of large scale mining excavators used in Bolidens Aitik copper mine in Sweden. Because of how much wear and tear the bucket teeth are exposed to, there is a need to better understand the wear behaviour of the teeth and for the whole bucket in general. This understanding can then be used to improve the service life of the teeth and other parts of the bucket and thus increase work efficiency and reduce downtime.

This project was divided into two parts. The first part consisted of regular field measurements to follow the wear on the bucket for about two weeks of digging and loading. The gathered data was then analysed to provide a better understand about the wear behaviour. The second part was to develop a numerical model that could predict the wear on the bucket and could be verified by the field measurements.

The field measurements consisted of seven 3D laser scans of the bucket starting with brand new teeth. At the time of the last scan, the buckets total loaded tonnage was approximately 542 kton and the excavator had operated in total of approximately 195 hours. After the raw data from the scans was gathered and analysed, various information about the wear behaviour on the teeth was achieved. The 3D scanned data was also used to provide a complete wear development cycle which allowed to track the wear of any point in the bucket. The method could also be used to create animations of the teeth as they were being worn. From the results, it was concluded that the wear rate for the teeth slowed down and even converged as the geometry changed due to wear. When comparing all nine teeth on the bucket, it was also found that the middle teeth on the bucket were most exposed to wear. The most worn tooth was found to lose around 50 kg of weight after approximately 117 operating hours, which accounts for 40 % of the original weight. The animations from the complete wear development results also showed how the individual teeth and the whole leading edge with all nine teeth were being worn as the buckets loaded tonnage increased from 0 to 542 kton.

The numerical model consisted of simulations of loading with the rocks being modelled with the Discrete Element Method (DEM). These were divided into four cases, the first being with the bucket with all new teeth. The second bucket with a mixture of new and worn teeth. The third bucket with all worn teeth and then finally the fourth bucket in which a new tooth geometry was tested. The numerical model showed promising results and potential for being a reliable way to predict the wear on the bucket. The results showed that both the penetration force and wear for the middle teeth was higher than the other neighbouring teeth. It also showed that the completely worn teeth had a lower wear rate than the new teeth which is in agreement with the results from field measurements. Other factors such as tooth shape and length were also observed to have a significant impact on the wear and penetration force. Lastly, the new teeth geometry also showed potential for design improvements in terms of wear resistance but can be further optimised. From the new teeth geometry, a suggestion was given for using an existing tooth system that might be more wear resistant.

Appropriate input selection for the estimation matrix is essential when modeling non-linear progression. In this study, the feasibility of the Gamma test (GT) was investigated to extract the optimal input combination as the primary modeling step for estimating monthly pan evaporation (EPm). A new artificial intelligent (AI) model called the co-active neuro-fuzzy inference system (CANFIS) was developed for monthly EPm estimation at Pantnagar station (located in Uttarakhand State) and Nagina station (located in Uttar Pradesh State), India. The proposed AI model was trained and tested using different percentages of data points in scenarios one to four. The estimates yielded by the CANFIS model were validated against several well-established predictive AI (multilayer perceptron neural network (MLPNN) and multiple linear regression (MLR)) and empirical (Penman model (PM)) models. Multiple statistical metrics (normalized root mean square error (NRMSE), Nash–Sutcliffe efficiency (NSE), Pearson correlation coefficient (PCC), Willmott index (WI), and relative error (RE)) and graphical interpretation (time variation plot, scatter plot, relative error plot, and Taylor diagram) were performed for the modeling evaluation. The results of appraisal showed that the CANFIS-1 model with six input variables provided better NRMSE (0.1364, 0.0904, 0.0947, and 0.0898), NSE (0.9439, 0.9736, 0.9703, and 0.9799), PCC (0.9790, 0.9872, 0.9877, and 0.9922), and WI (0.9860, 0.9934, 0.9927, and 0.9949) values for Pantnagar station, and NRMSE (0.1543, 0.1719, 0.2067, and 0.1356), NSE (0.9150, 0.8962, 0.8382, and 0.9453), PCC (0.9643, 0.9649, 0.9473, and 0.9762), and WI (0.9794, 0.9761, 0.9632, and 0.9853) values for Nagina stations in all applied modeling scenarios for estimating the monthly EPm. This study also confirmed the supremacy of the proposed integrated GT-CANFIS model under four different scenarios in estimating monthly EPm. The results of the current application demonstrated a reliable modeling methodology for water resource management and sustainability.

The effectiveness of a flat-plate solar collector was studied by using SiO2, Al2O3, Graphene, and graphene nanoplatelets nanofluids with distilled water as the working fluids. The energy efficiency was theoretically compared using MATLAB programming. The prepared carbon and metallic oxides nanomaterials were structurally and morphologically characterized via field emission scanning electron microscope. The study was conducted under different operating conditions such as different volume fractions (0.25%, 0.5%, 0.75% and 1%), fluid mass flow rate (0.0085, 0.017, and 0.0255 kg/s), input temperatures (30, 40, and 50 °C), and solar irradiance (500, 750, and 1000 W/m2). Nanofluids showed better thermophysical properties compared to standard working fluids. With the addition of the nanofluids SiO2, Al2O3, Gr and GNPs to the FPSC the highest efficiency of 64.45%, 67.03%, 72.45%, and 76.56% respectively was reached. The results suggested that nanofluids made from carbon nanostructures and metallic oxides can be used in solar collectors to increase the parameters of heat absorbed/loss compared to water only usage.